The invention relates to a method for producing an integrated circuit with a trench transistor structure.
Trench transistors are usually power transistors having a multiplicity of transistor structures of identical type, transistor cells, each having a gate electrode arranged in a trench. Source and body regions of individual transistor cells are arranged in semiconductor regions, mesa regions, between two adjacent trenches of such a component structure.
The body zone and the source zone—which is doped complementarily with respect to the body zone—of such trench transistors can be produced by implantation of dopant atoms into the mesa regions and by subsequent indiffusion of the implanted dopant atoms. In this case, proceeding from a surface of the semiconductor body, the dopant atoms of the body zone are indiffused further than those of the source zone, such that a pn junction between the source zone and the body zone is formed.
In component arrangements having a trench transistor it may be necessary for various reasons to produce a semiconductor zone of the same conduction type as the source zone of the transistor in the semiconductor body outside the cell array with the transistor cells. Such a semiconductor zone is a “channel stopper”, for example, which can be provided in the edge region of the semiconductor body and which serves in a known manner for interrupting a charge carrier channel in the edge region of the semiconductor body or for terminating the channel.
For these and other reasons, there is a need for the present invention.